Rumex longifolius; the Northern Dock is the largest of all dock-species common in Iceland. It has crispy / undulating leaf margins. The leaves are narrow, but unlike the common sorrel and the sheep's sorrel it has no appendages at the base. It is an introduced species and grows in human-disturbed soils (waste dumps, road-sides etc.)
Leaf shapes of the common sorrel species on Iceland
| Rumex acetosa | Rumex acetosella |
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| Rumex longifolius | Oxyria digyna |
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